(PHP 5 >= 5.1.0)
stream_wrapper_unregister — Unregister a URL wrapper
Allows you to disable an already defined stream wrapper. Once the wrapper has been disabled you may override it with a user-defined wrapper using stream_wrapper_register() or reenable it later on with stream_wrapper_restore().
成功时返回 TRUE， 或者在失败时返回 FALSE.